Rotary piston internal combustion engine of trochoidal construction

ABSTRACT

A rotary piston internal combustion engine of trochoidal construction which consists essentially of lateral parts and at least of one housing casing, in case of multi-disk internal combustion engines, of one or several intermediate parts, provided with hollow spaces for the accommodation of the cooling medium in each housing part and with ribs arranged in the hollow spaces; the ribs and/or the inner walls of the housing parts, particularly of the housing casing are provided with turbulenceproducing projections, preferably within the area of the minor axis in the hot arc.

1 States Patent 1' [451 Sept. 17, 11974 1 ROTARY PISTON INTERNALCOMBUSTION ENGINE OlF TROCIIOIDAL CONSTRUCTION [75] Inventor: HeinzlLaimm, Esslingen-St.

Bernhardt, Germany [73] Assignee: Daimler-Benz Aktiengesellschaft,

Stuttgart, Germany 22 Filed: Feb. 2, 1973 21 Appl. No.: 329,194

[30] Foreign Application Priority Data Feb. 3, 1972 Germany 2205015 [52]US. C1. 418/83, 123/801 [51] Int. Cl.... F0lc 21/06, F040 29/04, F02b55/10 [58] Field of Search 418/60, 61 A, 83;

[56] References Cited UNITED STATES PATENTS Froede 418/83 3,313,2764/1967 Ito ct n1. 418/83 3,561,894 2/1971 King 418/61 A 3,588,296 6/1971Toyuma r t r 418/83 3,644,070 2/1972 Lcrmusiaux 418/83 PrimaryExaminer-John J. Vrablik Attorney, Agent, or FirmCraig & Antonelli [5 7]ABSTRACT A rotary piston internal combustion engine of trochoidalconstruction which consists essentially of lateral parts and at least ofone housing casing, in case of multi-disk internal combustion engines,of one or several intermediate parts, provided with hollow spaces forthe accommodation of the cooling medium in each housing part and withribs arranged in the hollow spaces; the ribs and/or the inner walls ofthe housing parts, particularly of the housing casing are provided withturbulence-producing projections, preferably within the area of theminor axis in the hot arc.

28 C1aims,'4 Drawing Figures MENIEHSEPI mm SHEET 1 BF 2 HG. f

The present invention relates to a rotary piston internal combustionengine of trochoidal construction, consisting essentially of lateralhousing parts and of at least one housing casing, inmulti-disk internalcombustion engines of one or several intermediate parts, with hollowspaces for the accommodation of a cooling medium in each housing partand with ribs arranged in the hollow spaces.

In rotary piston internal combustion engines which are adapted to beloaded highly, temperatures occur ever so often at the casing runningsurfaces, especially in the spark plug proximity which exceed thepermissive limits.

These temperatures may be due both to the combustion as also to aninadequate cooling.

During unfavorable operating conditions of the internal combustionengine, steam or vapor bubbles form at the hottest places along therough skin of the casting of the housing parts, which have the effect ofan insulating layer and negatively influence the cooling effect.Additionally, they also enhance the formation of deposits out of thecooling medium (for example, lime) locally at these places.

Furthermore, a trouble-free feed of the cooling medium is not assured bythe tom-along and enclosed vapor bubbles in the cooling medium.

It is the aim of the present invention to undertake measures whichprevent beforehand locally occurring overheating appearances in that theproduced heat is rapidly and reliably conducted away from the casingrunning surface.

The underlying problems are solved according to the present invention inthat the ribs and/or inner walls of the housing parts, especially of thehousing casing are provided in the hot arc with turbulence-producingprojections preferably within the area of the minor axis.

In an advantageous embodiment according to the present invention, theprojections may be constructed nose-like.

Not only a turbulence preventing the vapor bubble formation is producedby the arrangement of the projections in the hollow spaces, whichturbulence remains nearly preserved over a longer distance, but also asurface enlargement favorable for the heat removal is attained thereby.

Accordingly, it is an object of the present invention to provide arotary piston internal combustion engine of trochoidal constructionwhich avoids by simple means the aforementioned shortcomings anddrawbacks encountered in the prior art.

Another object of the present invention resides in a rotary pistoninternal combustion engine of trochoidal construction which effectivelyprevents temperatures at the casing running surface that exceed thepermissive limits.

A further object of the present invention resides in a rotary pistoninternal combustion engine which is characterized by an improved coolingefficiency.

Still a further object of the present invention resides in a rotarypiston internal combustion engine of trochoidal construction whicheffectively eliminates the formation of vapor bubbles thereby improvingthe cooling effectiveness.

Another object of the present invention resides in a cooling system fora rotary piston internal combustion engine, especially of trochoidalconstruction, which far-reachingly precludes the formation of depositsout of the cooling medium.

These and further objects, features and advantages of the presentinvention will become more apparent from the following description whentaken in connection with the accompanying drawing which shows, forpurposes of illustration only, one embodiment in accordance with thepresent invention, and wherein:

FIG. 1 is a partial cross-sectional view through a housing casing inproximity of the minor axis of an engme;

FIG. 2 is a cross-sectional view, on an enlarged scale, through theinner wall of the housing casing facing the running surface.

FIG. 3 is a partial cross-sectional view of a rotary piston internalcombustion engine taken along the line Ill- -III of FIG. 1; and

FIG. 4 is a partial cross-sectional view of a multi-disk rotary pistoninternal combustion engine according to the present invention.

Referring now to the drawing wherein like reference numerals are usedthroughout the various views to designate like parts, and moreparticularly to FIG. I, a housing casing generally designated byreference numeral I of a rotary piston internal combustion engine is,according to this figure, provided with a hollow space 2 for theaccommodation of a cooling medium. Ribs 3 and 4 are arranged in thehollow space 2 which extend both at a predetermined angle (ribs 3) asalso parallel to the flow direction of the cooling medium (ribs 4).

Within the area of the hot arc of the internal combustion engine, i.e.,-as viewed in the direction of rotation of the piston P-from a pointupstream or in front of the minor axis a (FIG. 3) in the hot arc up toshortly in front or upstream of the minor axis in the cold arc betweenthe exhaust channel 13 and inlet channel 114 FIG. 3, nose-likeprojections are arranged at the ribs 3 and 4 as well as at a spark plugboss 5 disposed ahead of the minor axis a and at each inner wall 6 ofthe housing casing ll, which projections produce a turbulenceadvantageous for the cooling medium and effective over the entire widthof the housing casing.

The projections which are designated by reference numeral 7 are disposedover the entire circumference of the spark plug boss 5. Two projections8 each are arranged at the ribs 3 and 41- at each longitudinal sidethereof.

Especially the inner wall 6 facing the casing running surface 10 isprovided according to FIG. 2 with a large number of projections 9whereas the projections 12 arranged at the lateral walls llll of thehousing casing I have a larger spacing from one another.

FIG. 4 illustrates a multi-disk construction wherein a pair of housingcasings l are provided with an intermediate housing part 15 disposedbetween the casings. Each of the casings are provided with a hollowspace 2 for the accommodation of a cooling medium and include ribs, onlyone of which is shown in FIG. 5, and nose-like projections 8, 9, 12arranged at the ribs, running surface and lateral walls, respectively,of the casings ll.

Possibly also the adjacent lateral or intermediate parts may be providedwithin the adjoining area of the trochoidal contour of the casingrunning surface-within the area near the spark plug bosswith projectionsserving for creating a turbulence of the cooling medium.

The danger of the vapor bubble formation and therewith an impairment ofthe cooling medium supply is thereby completely eliminated.

While I have shown and described two embodiments in accordance with thepresent invention, it is understood that the same is not limited theretobut is susceptible of numerous changes and modifications as known tothose skilled in the art, and I therefore do not wish to be limited tothe details shown and described herein but intend to cover all suchchanges and modifications as are encompassed by the scope of theappended claims.

What I claim is:

1. An arrangement for a rotary piston internal combustion engineincluding at least one housing casing and lateral housing parts, thehousing casing being provided with hollow spaces for the accommodationof a cooling medium the arrangement comprising: at least one first ribmeans disposed in the hollow space arranged parallel to the flowdirection of the cooling medium, at least one second rib means disposedin the hollow space arranged at a predetermined angle to the flowdirection of the cooling medium, and projection means provided on atleast one of said first and second rib means for producing turbulence ofthe cooling medium.

2. A rotary piston internal combustion engine arrangement according toclaim 1, wherein the housing casing includes inner walls, and wherein atleast one of said inner walls is provided with projection means.

3. A rotary piston internal combustion engine arrangement according toclaim 1, including a spark plug boss means projecting into a respectivehollow space and wherein projection means are provided about the entirecircumference of said spark plug boss means 4. A rotary piston internalcombustion engine arrangement according to claim 1, wherein said housingcasing includes a running surface and inner wall, and wherein at leastone of said inner walls adjoins said running surface, projection meansbeing disposed on said last-mentioned inner wall and extending in adirection facing away from said running surface.

5. A rotary piston internal combustion engine arrangement according toclaim 1, wherein said projection means are of noselike construction.

6. A rotary piston internal combustion engine arrangement according toclaim 5, wherein said turbulence-producing projection means are arrangedat least within the area of the minor axis in thehot arc of the engine.

7. A rotary piston internal combustion engine arrangement according toclaim 1, wherein said first and second rib means are of elongatedconfiguration, said projection means being provided along thelongitudinal sides thereof.

8. A rotary piston internal combustion engine arrangement according toclaim 7, wherein said first rib means extends in the longitudinaldirection of a respective hollow space.

9. A rotary piston internal combustion engine arrangement according toclaim 8, wherein said first rib means are disposed substantiallycentrally in the hollow space said second rib means being disposedlaterally of the center longitudinal plane of the hollow space.

10. A rotary piston internal combustion engine arrangement according toclaim 1, wherein said projection means includes a plurality of spacednoselike projections provided on both of said first and second ribmeans.

11. A rotary piston internal combustion engine arrangement according toclaim 10, wherein said housing casing includes a pair of spaced lateralinner walls, and wherein spaced projection means are disposed on atleast one of said lateral inner walls.

12. A rotary piston internal combustion engine arrangement according toclaim 1, wherein said housing casing includes a pair of spaced lateralinner walls, and wherein projection means are disposed on at least oneof said lateral inner walls.

13. A rotary piston internal combustion engine arrangement according toclaim 12, wherein projection means are disposed on both of said lateralinner walls.

14. A rotary piston internal combustion engine arrangement according toclaim 13, wherein said housing casing includes a running surface and aninner wall adjoining said running surface, and wherein projection meansare disposed on said last-mentioned inner wall.

15. A rotary piston internal combustion engine arrangement according toclaim 13, wherein projection means are disposed on both of said lateralinner walls.

16. A rotary piston internal combustion engine arrangement according toclaim 15, wherein said housing casing includes a running surface and aninner wall adjoining said running surface, and wherein projection meansare disposed on said last-mentioned inner wall.

17. A rotary piston internal combustion engine arrangement according toclaim 1, wherein said turbulence-producing projection means are arrangedat least within the area of the minor axis in the hot arc of the engine.

18. A rotary piston internal combustion engine arrangement according toclaim 17, wherein the engine is of trochoidal construction.

19. A rotary piston internal combustion engine arrangement according toclaim 17, wherein the internal combustion engine is of multi-diskconstruction, and wherein at least one intermediate housing part isdisposed between two adjoining housing casing, each of said housingcasings including a hollow space for the accommodation of a coolingmedium.

20. A rotary piston internal combustion engine according to claim 17,wherein the housing casing in cludes inner walls, and wherein at leastone of said inner walls is provided with turbulence-producing projectionmeans.

21. A rotary piston internal combustion engine arrangement according toclaim 20, wherein said projection means are of nose-like construction.

22. A rotary piston internal combustion engine arrangement according toclaim 21, including a spark plug boss means projecting into a respectivehollow space, and wherein projection means are provided about the entirecircumference of said spark plug boss means.

23. A rotary piston internal combustion engine arrangement according toclaim 22, wherein said first and second rib means are of elongatedconfiguration, said projection means being provided along thelongitudinal sides thereof.

24. A rotary piston internal combustion engine arrangement according toclaim 23, wherein said first rib means extends in the longitudinaldirection of a respective hollow space.

25. A rotary piston internal combustion engine arrangement according toclaim 24, wherein said first rib means are disposed substantiallycentrally in the hollow space, said second rib means being disposedlaterally of the center longitudinal plane of the hollow space.

26. A rotary piston internal combustion engine arrangement according toclaim 25, wherein said housing casing includes a running surface, andwherein said at least one of said inner walls of said housing casingadjoins said running surface, projection means being disposed on saidlast mentioned inner wall and extending in a direction away from saidrunning surface.

27. A rotary piston internal combustion engine arrangement according toclaim 26, wherein said housing casing includes a pair of spaced lateralinner walls, and wherein projection means are disposed on at least oneof said lateral inner walls.

28. A rotary piston internal combustion engine arrangement according toclaim 27, wherein projection means are disposed on both of said lateralinner walls. l

1. An arrangement for a rotary piston internal combustion engineincluding at least one housing casing and lateral housing parts, thehousing casing being provided with hollow spaces for the accommodationof a cooling medium the arrangement comprising: at least one first ribmeans disposed in the hollow space arranged parallel to the flowdirection of the cooling medium, at least one second rib means disposedin the hollow space arranged at a predetermined angle to the flowdirection of the cooling medium, and projection means provided on atleast one of said first and second rib means for producing turbulence ofthe cooling medium.
 2. A rotary piston internal combustion enginearrangement according to claim 1, wherein the housing casing includesinner walls, and wherein at least one of said inner walls is providedwith projection means.
 3. A rotary piston internal combustion enginearrangement according to claim 1, including a spark plug boss meansprojecting into a respective hollow space and wherein projection meansare provided about the entire circumference of said spark plug bossmeans
 4. A rotary piston internal combustion engine arrangementaccording to claim 1, wherein said housing casing includes a runningsurface and inner wall, and wherein at least one of said inner wallsadjoins said running surface, projection means being disposed on saidlast-mentioned inner wall and extending in a direction facing away fromsaid running surface.
 5. A rotary piston internal combustion enginearrangement according to claim 1, wherein said projection means are ofnoselike construction.
 6. A rotary piston internal combustion enginearrangement according to claim 5, wherein said turbulence-producingprojection means are arranged at least within the area of the minor axisin the hot arc of the engine.
 7. A rotary piston internal combustionengine arrangement according to claim 1, wherein said first and secondrib means are of elongated configuration, said projection means beingprovided along the longitudinal sides thereof.
 8. A rotary pistoninternal combustion engine arrangement according to claim 7, whereinsaid first rib means extends in the longitudinal direction of arespective hollow space.
 9. A rotary piston internal combustion enginearrangement according to claim 8, wherein said first rib means aredisposed substantially centrally in the hollow space said second ribmeans being disposed laterally of the center longitudinal plane of thehollow space.
 10. A rotary piston internal combustion engine arrangementaccording to claim 1, wherein said projection means includes a pluralityof spaced noselike projections provided on both of said first and secondrib means.
 11. A rotary piston internal combustion engine arrangementaccording to claim 10, wherein said housing casing includes a pair ofspaced lateral inner walls, and wherein spaced projection means aredisposed on at least one of said lateral inner walls.
 12. A rotarypiston internal combustion engine arrangement according to claim 1,wherein said housing casing includes a pair of spaced lateral innerwalls, and wherein projection means are disposed on at least one of saidlateral inner walls.
 13. A rotary piston internal combustion enginearrangement according to claim 12, wherein projection means are disposedon both of said lateral inner walls.
 14. A rotary piston internalcombustion engine arrangement according to claim 13, wherein saidhousing casing includes a running surface and an inner wall adjoiningsaid running surface, and wherein projection means are disposed on saidlast-mentioned inner wall.
 15. A rotary piston internal combustIonengine arrangement according to claim 13, wherein projection means aredisposed on both of said lateral inner walls.
 16. A rotary pistoninternal combustion engine arrangement according to claim 15, whereinsaid housing casing includes a running surface and an inner walladjoining said running surface, and wherein projection means aredisposed on said last-mentioned inner wall.
 17. A rotary piston internalcombustion engine arrangement according to claim 1, wherein saidturbulence-producing projection means are arranged at least within thearea of the minor axis in the hot arc of the engine.
 18. A rotary pistoninternal combustion engine arrangement according to claim 17, whereinthe engine is of trochoidal construction.
 19. A rotary piston internalcombustion engine arrangement according to claim 17, wherein theinternal combustion engine is of multi-disk construction, and wherein atleast one intermediate housing part is disposed between two adjoininghousing casing, each of said housing casings including a hollow spacefor the accommodation of a cooling medium.
 20. A rotary piston internalcombustion engine according to claim 17, wherein the housing casingincludes inner walls, and wherein at least one of said inner walls isprovided with turbulence-producing projection means.
 21. A rotary pistoninternal combustion engine arrangement according to claim 20, whereinsaid projection means are of nose-like construction.
 22. A rotary pistoninternal combustion engine arrangement according to claim 21, includinga spark plug boss means projecting into a respective hollow space, andwherein projection means are provided about the entire circumference ofsaid spark plug boss means.
 23. A rotary piston internal combustionengine arrangement according to claim 22, wherein said first and secondrib means are of elongated configuration, said projection means beingprovided along the longitudinal sides thereof.
 24. A rotary pistoninternal combustion engine arrangement according to claim 23, whereinsaid first rib means extends in the longitudinal direction of arespective hollow space.
 25. A rotary piston internal combustion enginearrangement according to claim 24, wherein said first rib means aredisposed substantially centrally in the hollow space, said second ribmeans being disposed laterally of the center longitudinal plane of thehollow space.
 26. A rotary piston internal combustion engine arrangementaccording to claim 25, wherein said housing casing includes a runningsurface, and wherein said at least one of said inner walls of saidhousing casing adjoins said running surface, projection means beingdisposed on said last mentioned inner wall and extending in a directionaway from said running surface.
 27. A rotary piston internal combustionengine arrangement according to claim 26, wherein said housing casingincludes a pair of spaced lateral inner walls, and wherein projectionmeans are disposed on at least one of said lateral inner walls.
 28. Arotary piston internal combustion engine arrangement according to claim27, wherein projection means are disposed on both of said lateral innerwalls.